Time for another short quiz! This one is a little tougher than the last one, I believe. What is the mechanism for the following transformation?
And hey, no looking in SciFinder, Reaxys, Wikipedia, books or the literature. Only pencil, paper and brains are allowed.
The first one to submit the correct answer down below will get a nice prize sent to him or her in the physical world. Go!
nucleophilic ipso-substitution on bromide? (with NH2-)
I mean via like-Meisenheimer complex
Looks to me like a nucleophilic acyl substitution, with attack at the Br centre and stabilization of the intermediate by extensive conjugation and charge stabilization due to negative charge landing on electronegative nitrogens. Expulsion of Br should give KBr as a nice solid.
Just an undergrad’s idea.
Hadriel
ANRORC obviously, but it’s hard to draw it properly
CONGRATS!!
ANRORC is the correct answer indeed. See a thorough explanation with good proofs here.
Dmitry B, please email me your shipping address so I can send you the prize!
May be the substrate can be considered as imidoyl bromide analogue, and accordingly the mechanism would involve addition-elimination sequence, the addition part being facilitated by delocalisation of the negative charge over two N-s
And, BTW, what does ANRORC stand for?
It might have been a bit easier if you’d put the correct reagents? It would have saved us drawing 4+2’s using the Potassium salt of Diimide.
wOOt? You never worked with the adduct between potassium hydride and atmospheric nitrogen?
Seriously, haha… it should be KNH2, of course. I promise to correct the image before the last day of the Maya calendar.
RORC is ring-opening, ring-closing, I think, and N is nucleophilic, but I don’t remember what A is.
Addition Nucleophilic Ring-Opening Ring-Closing
Thanks for a fun exercise. A bit anticlimactic after having figured out a good mechanism with KN2H though!